> And why are these build systems necessary in the first place? Because depending on the use case you generally need to build the same software in a lot of dif

> And why are these build systems necessary in the first place? Because depending on the use case you generally need to build the same software in a lot of different configurations : debug / release runtimes on windows, various sanitizers, static / dynamic / dynamic with LTO, you also want to build some files only on some platforms, you want your users to be able with / without tests / examples / implementations of various types (e.g. enable / disable network protocols or media codecs at build time for the two most common use cases I know), enable / disable profiling or coverage or tracing support... add a flag for having split debug info but you need to disable it if your users run ubuntu 16.04 because here it's broken, add a flag for linking with lld but you need to disable it on macos because it's broken, change debug mode to -Og if you're on a CI machine because -O0 takes too much space and you fill the Travis CI vm, except if you're on a worker with a recent enough toolchain to support -Wl,--compress-debug-sections=zlib e.g. look at the configurability of something like ffmpeg : https://paste.ofcode.org/zBhsKWiSk3Gn73bkgfA9Yk https://paste.ofcode.org/zBhsKWiSk3Gn73bkgfA9Yk or qt : https://paste.ofcode.org/wmZZX9emiNr2uPksceZNz6 https://paste.ofcode.org/wmZZX9emiNr2uPksceZNz6 or one of the project I work on - most of the config flags here were added after the request of some users who wanted to be able to make a leaner build in some specific case ; making multiple shared libraries is a no-go first because then your users complain that they don't which of the five libraries they have to add to their system, and also because you loose LTO and have a lot of duplication of template instantiations (or monomorphized generics as it is said in Rust parlance): https://github.com/OSSIA/libossia/blob/master/cmake/OssiaOptions.cmake https://github.com/OSSIA/libossia/blob/master/cmake/OssiaOpt... You rarely have complex problems with simple solutions.